In Situ Coating of Li₇P₃S₁₁ Electrolyte on CuCo₂S₄/Graphene Nanocomposite as a High-Performance Cathode for All-Solid-State Lithium Batteries

A cathode material, CuCo2S4/graphene@10%Li7P3S11, is reported for all-solid-state lithium batteries with high performance. The electrical conductivity of CuCo2S4 is improved by compounding with graphene. Meanwhile, Li7P3S11 electrolyte is coated on the surface of CuCo2S4/graphene nanosheets to build an intimate contact interface between the solid electrolyte and the electrode effectively, facilitating lithium-ion conduction. Benefitting from the balanced and efficient electronic and ionic conductions, all-solid-state lithium batteries using CuCo2S4/graphene@10%Li7P3S11 composite as cathode materials demonstrate superior cycling stability and rate capabilities, exhibiting an initial discharge specific capacity of 1102.25 mAh g–1 at 50 mA g–1 and reversible capacity of 556.41 mAh g–1 at a high current density of 500 mA g–1 after 100 cycles. These results demonstrate that the CuCo2S4/graphene@10%Li7P3S11 nanocomposite is a promising active material for all-solid-state lithium batteries with superior performances.